Chapter 4 Setup; Mounting And Alignment - THORLABS LCC3111H User Manual

Liquid Crystal Noise Eater
Chapter 4 Setup
4.1.

Mounting and Alignment

The noise eater is designed to work with linearly polarized input light aligned with
the direction of the arrow near the input aperture. Linearly polarized light and
proper alignment of the direction of polarization are important for achieving the
best results from the noise eater.
In order to minimize optical losses, the noise eater does not have an input
polarizer. If the incident light is not linearly polarized, a linear polarizer (such as
our LPVIS or LPNIR polarizers) should be used before the noise eater.
If the incident light is linearly polarized but is not aligned exactly vertically or
horizontally, a half-wave plate can be used before the noise eater to rotate the
polarization axis. As shown in the photo below, the noise eater's cage mount can
be used along with a CRM1 cage rotation mount to rotate the half-wave plate,
thus aligning the polarization axis with the noise eater.
Figure 2 CRM1 Cage Rotation Mount holding a Mounted Half-Wave Plate
(such as the WPH10M-633), secured to the LCC3111H Noise Eater with ER
Cage Rods
For post mounting, the noise eater is equipped with two 8-32 (M4) threaded
holes. These holes are offset by 90°, so that light with a vertical or horizontal
polarization axis can be aligned with the noise eater. The four 4-40 holes on the
front of the noise eater can also be used to mount the noise eater in either a
horizontal or vertical orientation using the Thorlabs Cage System
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Rev C, Dec 8, 2015